//1.变量与常量
//格式：var variableName: DataType = initialValue
var agge: Int = 18
var name:String = "John"
var oneChar:Character = "a"
print(agge)
print(name)
print(oneChar)


//2.常量
//let constantName: DataType = initialValue
let pi: Double = 3.14
let maxAge: Int = 100
print(pi)
print(maxAge)

